类风湿性关节炎（RA）是一种慢性自身免疫性疾病，其特征是对称性关节炎。薏仁油（CSO）已被证明能减轻胶原诱导的关节炎（CIA）大鼠中的炎症。然而，CSO对RA滑膜血管新生的影响尚不明确。本研究旨在探索CSO是否能抑制RA滑膜血管新生，并揭示潜在机制。采用CIA大鼠模型，分别在体内进行为期四周的不同剂量的CSO处理。记录关节炎指数、爪肿胀和体重以评估临床症状。采用苏木精伊红染色、圣佛尼绿染色、微CT、免疫组织化学染色和免疫荧光（IF）染色检查滑膜和关节组织的变化。通过酶联免疫吸附测定评估血清中HIF-1α和VEGF-A水平。通过刺激大鼠成纤维样滑膜细胞（FLS）使用肿瘤坏死因子-α（TNF-α）建立体外炎症模型。通过细胞计数试剂盒-8测试测定CSO和TNF-α的最佳刺激浓度。采用伤口愈合和Transwell迁移实验来确定FLS的迁移能力。通过IF染色评估FLS中HIF-1α的核移位。通过Western blot检测SIRT1、HIF-1α、VEGF-A和CD31的蛋白水平。将隔离的主动脉环与重组大鼠VEGF-A 165（VEGF-A165）诱导结合以观察CSO对体外血管生成的抑制作用。CSO减轻了CIA大鼠的关节炎进展，减轻了滑膜和关节组织的组织病理学恶化，显著抑制了标记为CD31+/αSMA-的未成熟血管，并减少了VEGF-A165诱导的主动脉环中的微血管。此外，它提高了CIA大鼠和TNF-α诱导的FLS中的SIRT1蛋白水平，但降低了HIF-1α和VEGF-A蛋白水平。此外，CSO抑制了TNF-α诱导的FLS的迁移能力和HIF-1α核移位。最后，抑制TNF-α诱导的FLS中的SIRT1水平增强了它们的迁移能力、HIF-1α核移位和HIF-1α、VEGF-A和CD31蛋白水平，而CSO对TNF-α诱导的FLS的抑制作用受到严重限制。该研究表明，CSO通过抑制CIA大鼠中的HIF-1α/VEGF-A信号通路来缓解滑膜血管新生，并通过SIRT1发挥作用。© 2023年。国际中医学会和BioMed Central有限公司。

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by symmetric arthritis. Coix Seed Oil (CSO) has been shown to reduce inflammation in collagen induced arthritis (CIA) rats. However, the effect of CSO on synovial angiogenesis in RA is unknown. In this study, we aimed to explore whether CSO could inhibit RA synovial angiogenesis and elucidate the underlying mechanisms.CIA rat models were established and subjected to different doses of CSO treatments for four weeks in vivo. Arthritis index, paw swelling, and weight were recorded to assess clinical symptoms. Hematoxylin and Eosin staining, Safarnin O fast green staining, Micro-CT, Immunohistochemical, and Immunofluorescence (IF) staining were performed to examined changes in synovial and joint tissues. The serum HIF-1α and VEGF-A levels were evaluated through enzyme-linked immunosorbent assay. Fibroblast-like synoviocytes (FLS) of rats was stimulated with tumor necrosis factor-α (TNF-α) for developing inflammatory model in vitro. Optimal concentrations of CSO and TNF-α for stimulation were measured through Cell Counting Kit-8 test. Wound healing and Transwell migration experiments were employed to determine FLS migratory ability. IF staining was performed to assess HIF-1α nuclear translocation in FLS. Protein levels of SIRT1, HIF-1α, VEGF-A, and CD31 were assessed through Western blot. The isolated aortic rings were induced with recombinant rat VEGF-A 165 (VEGF-A165) to observe the CSO inhibitory impact on angiogenesis ex vivo.CSO attenuated the progression of arthritis in CIA rats, mitigated histopathological deterioration in synovial and joint tissues, significantly inhibited immature vessels labeled with CD31+/αSMA-, and reduced the micro-vessels in VEGF-A165 induced aortic rings. Moreover, it upregulated SIRT1 protein levels in CIA rats and TNF-α induced FLS, but decreased HIF-1α and VEGF-A protein levels. Furthermore, CSO inhibited the migration ability and HIF-1α nuclear translocation of TNF-α induced FLS. Finally, suppressing SIRT1 levels in TNF-α induced FLS enhanced their migration ability, HIF-1α nuclear translocation, and the protein levels of HIF-1α, VEGF-A, and CD31, whereas the inhibitory effect of CSO on TNF-α induced FLS was severely constrained.This study indicates that CSO can alleviate synovial angiogenesis through suppressing HIF-1α/VEGF-A signaling pathways via SIRT1 in CIA rats.© 2023. International Society for Chinese Medicine and BioMed Central Ltd.